A very common need in the world of ANSYS FEA simulation is to write text to a text file from within Mechanical APDL. Sometimes you are running in MAPDL, sometimes you are using ANSYS Mechanical but you still need to write stuff out using APDL with a code snippet. The way most people do that is with *VWRITE. <\/p>\n
Originally written to write out data in arrays, it is a very flexible and powerful command that can be used to write pretty much any type of formatted output. Something that every ANSYS user should have in their back pocket.<\/p>\n
*VWRITE, Par1, Par2, Par3, Par4, Par5, Par6, Par7, Par8, Par9, Par10, Par11, Par12, Par13, Par14, Par15, Par16, Par17, Par18, Par19<\/strong><\/p>\n Looks pretty simple right, just *vwrite and list what you want printed. But there is a lot more to this command.<\/p>\n First off you need to open up a file to write to. You have a couple of options.<\/p>\n Now you have a place to write to, next you need to use *VWRITE to write. *VWRITE is a unique command because it actually uses two lines. The first contains *VWRITE and a list of parameters and\/or arrays to write and the second contains a format statement. We will cover the first line first, and the format second.<\/p>\n As you can see from the command, you can have up to 19 parameters listed on a *VWRITE command. PAR1 through PAR19 can be array, scalar, or character parameters. They can also be a constant. This is where the real flexibility comes in. You can do something like (just look at the *VWRITE line, we will talk about the rest further on):<\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/div>\n<\/div>\n This mixes characters, arrays, and constants in one command. As output you get:<\/p>\n <\/div>\n Array Parameters<\/font><\/em><\/p>\n The first thing you will notice is no *do loop. If you supply an array parameter, *vwrite loops on the parameter from the given index (1 in this case) to the end of the array. But if you don\u2019t want the whole array written, you can control by placing *VLEN and\/or *VMASK in front of the *VWRITE command:<\/p>\n You can have a multiple dimensions on your array. *VWRITE only increments the first index. Say you specify X, Y, and Z coordinates in an array call xyz. It would look like:<\/p>\n *VWRITE,xyz(1,1),XYZ(1,3),XYZ(1,3) String Parameters<\/font><\/em><\/p>\n Being an older program, you are limited in what you can do with character parameters. You are limited to 8 characters. So you just use a long string parameter several times and increment the index by 8:<\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/div>\n<\/div>\n Kind of hokey, but it works.<\/p>\n Integers<\/em><\/p>\n Sigh. This is the one thing that I\u2019m not fond of in *VWRITE. The original command did not support outputting integer values. That is because the FORTRAN I descriptor was not supported, and ANSYS stores everything as an integer anyhow. But people needed to output integer values so they took the \u2018C\u2019 format routines for *MSG and made them work with *VWRITE. So you can do a %I. See the section on \u2018C\u2019 formatting below for more information on this.<\/p>\n Close the File<\/font><\/em><\/p>\n Before you can do anything with the file you create you need to close it. Not to hard: *CFCLOSE does the trick.<\/p>\n Other Stuff you Need to Know<\/em><\/p>\n Don\u2019t put a blank in there. If you do, *vwrite stops looking at parameters. So if you need a blank in your file, put in a space \u2018 \u2018 or use the X FORTRAN descriptor.<\/p>\n Be aware of *CFWRITE as well. It is a way to write APDL commands to a file. If what you want to do is have your macro write a macro, *CFWRITE is better because you don\u2019t have to do format statements. And those can be a pain when you need commas.<\/p>\n If your arrays are of different lengths, *VWRITE will loop for the length of the longest array. Any shorter arrays will be replaced with zeros for number arrays and blanks for character\/string arrays.<\/p>\n You can not use *VWRITE by pasting or typing into the command line. You have to read it from a file.<\/p>\n The key, and the difficult part of using *VWRITE is the format statement. We recommend that you use the FORTRAN formatting when you are writing out large amounts of columnar data, and use the \u2018C\u2019 format if you are writing out text rich information for a report or to inform the user of something.<\/p>\n<\/h2>\n
A Lot More<\/h2>\n
\n
This opens the specified file for writing with *cfwrite and *vwrite commands. This is the preferred method.\n
By default *VWRITE output to standard output \u2013 the jobname.out (batch) file or the command window (interactive). So if you use \/output you can redirect to a file instead of the *.out or screen. We don\u2019t recommend this because other stuff might get written as well to the file.<\/li>\n<\/ol>\nParameter Arguments for *VWRITE<\/font><\/em><\/font><\/h3>\n
<\/pre>\n
1:<\/span> adiv = ' | '<\/pre>\n 2:<\/span> *dim,nds, ,10<\/pre>\n 3:<\/span> *dim,temps,,10<\/pre>\n 4:<\/span> *vfill,nds(1),ramp,1,1<\/pre>\n 5:<\/span> *vfill,temps(1),rand,70,1500<\/pre>\n 6:<\/span> *cfopen,vw1.out<\/pre>\n 7:<\/span> *VWRITE,'Temp: ',nds(1),temps(1),adiv, 'TREF: ',70<\/strong><\/pre>\n 8:<\/span> (A6,F8.0,g16.8,A3,A6,F10.4)<\/pre>\n 9:<\/span> *cfclose<\/pre>\nTemp: 1. 429.56308 | TREF: 70.0000
Temp: 2. 263.55403 | TREF: 70.0000
Temp: 3. 1482.8411 | TREF: 70.0000
Temp: 4. 605.95819 | TREF: 70.0000
Temp: 5. 782.33391 | TREF: 70.0000
Temp: 6. 1301.1332 | TREF: 70.0000
Temp: 7. 1119.4253 | TREF: 70.0000
Temp: 8. 202.87298 | TREF: 70.0000
Temp: 9. 1053.4121 | TREF: 70.0000
Temp: 10. 805.71033 | TREF: 70.0000<\/pre>\n\n
This will only write out nrow times, skipping based on ninc (defaults to 1)\n\n
*VLEN,1
*VWRITE,A(4)
(G16.8)<\/li>\n<\/ul>\n
You make a mask array of 0\u2019s and 1 that is the same size as your array, and supply it to *VMASK. *VWRITE will only write out values for your array if the mask array is not zero for the same index.<\/li>\n<\/ul>\n\n
(3G16.8)<\/p>\n<\/blockquote>\n 1:<\/span> *dim,mystring,string,80<\/pre>\n 2:<\/span> mystring(1) = 'This is a very long sentance'<\/pre>\n 3:<\/span> *cfopen,vw2.out<\/pre>\n 4:<\/span> *VWRITE,mystring(1), mystring(9), mystring(17), mystring(25), mystring(33)<\/pre>\n 5:<\/span> (5A) <\/pre>\n 6:<\/span> *cfclose<\/pre>\n<\/h2>\n
Formatting<\/h2>\n